People use boats to travel through the flooded area after the water level of the Brahmaputra River rises following heavy rainfall, at Balimuk village in Morigaon. Image Credit: ANI

Guwahati: Devastating floods in India's northeast that have killed scores of people also swamped a national park drowning six threatened rhinos and other wildlife, government officials said Tuesday.

Floods have begun to ease, Assam state Chief Minister Himanta Biswa Sarma said in a statement, noting the "water level of the Brahmaputra and its tributaries is below the danger level in most places".

More than 1.8 million people have been affected across 3,000 villages, as well as 72 killed since mid-May, according to state disaster officials.

Monsoon rains across South Asia from June to September offer respite from the summer heat and are crucial to replenishing water supplies, but also bring widespread death and destruction.

The intensity of rain and floods has increased in recent years, with experts saying climate change is exacerbating the problem.

As the waters recede, the impact on wildlife from the deluge is also being seen, including in Kaziranga National Park.

"Floods have affected humans and animals alike," Sarma said, adding officers had been "working round the clock to aid everyone".

On Monday, Sarma posted a video on social media of a stranded rhino calf, up to its chin in water, saying he had "instructed its immediate rescue".

Kaziranga is home to two-thirds of the world's remaining one-horned rhinos, classified as vulnerable on the International Union for Conservation of Nature Red List.

The park has 2,413 rhinos, according to a 2018 count.

Wildlife officers said six rhinos as well as scores of deer had been killed in recent days.

"Although there is higher ground for the shelter of the animals, the animals suffer when the high floods affect the park," said a senior park official, who was not authorised to speak to the media, confirming the animal deaths.

Kaziranga, a UNESCO world heritage site, is flooded almost every year, helping replenish water supplies and the ecological balance of the park.